Yarn is a textile formation made by spinning of a relatively short fibrous material into a long continuous unit. Raw cotton is used as one of the many input materials for yarn production. Machine yarns are wound onto coils for easy storage and further processing.
Yarn evenness and foreign fibers are important quality parameters in yarn. Yarn evenness refers to the variation in diameter along its length, as yarn has small changes in diameter along its length. There are numerous locations of thick and thin portions along the yarn length. This affects evenness of the yarn. Foreign fiber is the presence of foreign particles in the textile yarn. Textile yarn is generally white in color. Foreign fibers interfere with color homogeneity of the yarn. Yarn color analysis determines the presence of foreign fibers. Yarn evenness and foreign fibers are affected by quality of the materials used. Yarn evenness is also affected during manufacturing by spinning machines. As yarn is produced rapidly and in high volumes, manual inspection by human inspectors is not feasible, but rather, is impractical, and not possible.